Propiolyl halides and a method of making them



Patented Nov. 6, 1945 Frederic C. Schaefer, Greenwich, Conn., assignor to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware No Drawing. Application January 29, 1944, Serial N0.,520,323

4 Claims. (01. 200-544) This invention relates to the preparation propiolyl halides, suchas the chloride, bromide, and iodide. It includes the new products and their preparation by pyrolysis of the corresponding dihalo propionyl halide. It also includes the polymers of the propiolyl halides. This application is a continuation-in-part for my application Serial No. 439,951.

According to this invention the dihalo pro-. pionyl halide is pyrolyzed' toproduce the new propiolyl halide. The following examples which relate Particularly to the preparation of the chloro derivative are illustrative;

Example 1 Ninety-eight grams of alpha, beta dichloro propionyl chloride were pyrolyzed by being passed downward through a Pyrex tube (23 mm. internal diameter) packed with /4 inch Berl saddles for a length of 22 inches. The section of tube containing the saddles was heated with a 20-inch electric furnace to 450 C. The exit gases were condensed and the liquid product iractionally distilled. The entire pyrolytic system was evacuated to 200 mm. pressure throughout the pyrolysis. The dichloro propionyl chloride was introduced at a rate of 1.5 grams per minute. Fractionation of the product gave as the propiolyl chloride 9. material boiling at 59-61 C. at {100 mm. (N 1.4348) The process is not limited to pyrolysis at such a, high temperature or in an electric furnace. It is not necessary to carry out the reaction under reduced pressure. This is evident irom the fol lowing examples:

7 Example 2 I Eighty-seven grams of alpha, beta dichloro ,propionyl chloride were heated in a flask imder a 10-inch packed column. The contents were heated to a temperature of 170-210" C. for a perind of 1 to 2 hours. After pyrolysis was completed, the low boiling material which distilled below C. was collected and iractionally redistilled. A fraction boiling at '12-'75 C. was collected. (P1 315317) Emdmpleii v The propiolyl chloride obtained in Examplel was sealed up and allowed to stand. After a period oftime it had polymerized to a white crumbly solid which was lnfusible and somewhat resilient.

What I claim is:-

'1. The method of producing a propiolyl halide oi the class consisting of the chlorides, bromides,

and iodides which comprises pyrolyzing'arralpha beta dihalo propionyl halide at a temperature of at least C.

2. The method of producing propiolyl chloride which comprises pyrolyzing alpha, beta dichloro propionyl chloride at a temperature of at least 170 C.

3. The class of propiolyl halides consisting of the chloride, bromide, and iodide.

4. Propiolyl chloride.

FREDERIC 0. serum. 

